Slave cylinder assembly



March 4, 1952 H. L. FRlcK SLAVE CYLINDER ASSEMBLY original Filed Feb. 1,194e EL l -:H- INVENTOR HAROLD LFR/CK ATTORNEY Patented Mar. 4, 1952SLAVE CYLINDER ASSEMBLY Harold L. Frick, Detroit, Mich., assignor toHydraulic Brake Company, a corporation of Califor-nia substituted forabandoned application Serial No.

644,731, February 1,1946.

This application May 10, 1950, Serial N o. 161,202

8 Claims. (Cl. 18S-79.5)

This application is a substitute for my abandoned application SerialNumber 644,731, led February 1, 1946.

IThis invention relates to brakes and more par ticularly to means foradjusting the friction elements thereof.

The invention comprehends simple and enicient means for automaticallyadjusting the friction elements of a conventional brake proportionatelyto the wear of the lining on the friction element, so that when thebrake is at rest the friction elements may be supported in proper spacedrelation to the drum.

An object of the invention is to provide an automatically operativeadjuster for the friction element of a brake controlled by wear of thelining on the friction element.

Another object of the-invention is to provide an automatically operativeadjuster for the friction element of a conventional brake which may beeasily and quickly installed and will efficiently perform its intendedfunction.

Another object of the invention is to provide an automatically operativeadjuster for the friction element of a conventional brake which may bemanufactured as an accessory at low cost and easily installed in severaldifferent types of braking systems now in general use.

Yet another object of the invention is to pro vide an automaticallyoperative adjuster for the friction elements of a brake of the fluidpressure actuated type wherein adjusters may be sleeved on the thrustpins connecting the actuating means with the friction elements.

Other objects and advantages of the invention will appear from thefollowing description when taken in connection with the drawings forminga part of this specication, and in which:

Fig. l is a vertical sectional view of a brake illustrating theinvention as applied; and

Fig. 2 is a longitudinal sectional view of the fluid pressure actuatedmotor and the adjusters.

Referring to the drawings for more specific details of the invention, Irepresents a fixed support or backing plate adapted to be secured to anaxle or to an axle housing, and a rotatable drum I2 associated with thebacking plate is adapted to be secured to a wheel.

The backing plate has thereon spaced anchors I4 and I6 and a pair ofcorresponding, interchangeable friction elements or shoes I8 and 2d havetheir articulate ends pivoted on the anchors. Each of the shoes includesa web 22 supporting a rim 24 having suitably secured thereon a frictionlining 26 for cooperation with the drum.

A iiuid pressure actuated motor indicated generally at 28 is secured tothe backing plate lil between the force applying ends of the frictionelements or shoes. The motor includes a cylinder 3U having a port 32centrally disposed with relation to the length thereof, andcorresponding oppositely disposed pistons 34 and 36 are mounted forreciprocation in the cylinder.

Each of the pistons 34 and 36 carries a sealing ring 38 for inhibitingseepage of uicl from the cylinder past the piston. A cap 4U having aconcentrically disposed opening 42 is threaded in each end of thecylinder and held against displacement as by a lock washer 44, andretractile springs 46 are interposed between the pistons and the caps.

Thrust pins 48 suitably connect the pistons 34 and 36 to the forceapplying ends of the friction elements or shoes I8 and 20, andautomatically operative adjusting means for the friction elementsindicated generally at 5i) are carried on each of the thrust pins. Eachof the automatically operative adlusters B includes a heavy washer 52sleeved on the thrust pins. The washer has an arcuate end 54 seated onthe cap 4U and a conical recess 56 in its other end.l A cap 58 isthreaded on the washer and friction elements embracing the thrust pinare seated in the conical recess and urged into pressing engagement withthe pin by a spring 62 interposed between the friction elements and thecap.

rlhe caps 5i:` have spaced arms 64 adapted to stradale the shoes I8 and2o' at the force applying ends thereof and blocks 66 on the armscooperate with the drum.

Under normal operating conditions upon energization of the fluidpressure actuated motor 2t, the pistons 34 and 33 thereof are moved inopposite directions and during this movement of the pistons force istransmitted from the pistons through the thrust pins 48 to the forceapplying ends of the friction elements I8 and 2U, resulting in movementof the friction elements into engagement with the drum against theresistance of the retractile springs 4E, to effectively retard rotationof the drum. This operation inherently results in wear of the linings 26on the friction elements and this causes maladjustment of the brake.

Un the incident invention, the lining 26 on the friction elements andthe blocks 66 of the adjusters 5i) engage the drum concomitantly. Thelinings 2t are subjected to the usual wear incident to such an operationand the blocks B of the adjusters because of their low coeiiicient offriction resist wear. Accordingly there is a relative movement betweenthe friction elements and the adjusters 50, and this results in movementof the adjusters on the thrust pin to a slightly retracted positionwhere they are held by the friction members 56 urged into grippingengagement with the thrust pins by the springs 52.

Under this condition, upon completion of a breaking operation andrelease of applied pressure on the iiuid in the motors 28, the pistonsand 36 return to their respective retracted positions under theinfluence of the retractile springs 46 carrying with them the thrustpins 48 and the friction elements I8 and 20, and when returned to fullyretracted position the washers 52 of the adjusters seat on the heads ofthe cylinder lf3 and serve to support the friction elements in properspaced relation tothe drum.

Although this invention has been described in connection with certainspecific embodiments, the principles involved are susceptible ofnumerous other applications that `will readily occur to persons skilledin the art. The invention is, therefore, to be limited only as indicatedby the appended claims.

Having thus described the various features of the invention, what Iclaim as new and desire to secure 4by Letters Patent is:

14A brake comprising a movable member, a friction element associatedtherewith, a thrust member for moving the friction element intoengagement with the movable member, a xed member, and a stop membercoacting with the fixed member and frictionally engaging the movablemember and frictionally gripped on the thrust member andl movablethereon as the result of a differential in wear between the frictionelement and that part of the stop member engaging the movable member.

2. A brake comprising a movable member, a

vfriction element associated therewith, a thrust member for moving thefriction element into engagement with the movable member, a Xed member,a stop frictionally clamped to the thrust member coacting with the fixedmember and having a part adapted to engage the movable membersimultaneously with the friction element and movable on the thrustmember proportionally to adifferential in wear between the frictionelement and the part.

31A brake comprising a movable member, a friction element forcooperation therewith, a thrust pin for-moving the friction element intoengagement with the movable member and means for determining theretracted position of the thrust pin including a stop memberfrictionally clamped to the thrust pin and having a wear resisting partadapted to engage the movable member simultaneously with the frictionalelement and movable on the thrust pin proportionf ately to adifferential in wear between the friction element and the wearresistance part.

4. A brake comprising a rotatable drum, a friction element forcooperation therewith, a uid pressure actuated motor, a thrust pinconnecting the motor to the friction Yelement and automaticallyoperative means for adjusting the friction element with relation to thedrum, including a stop member frictionally clamped to the `thrust pinhaving a wear resisting part adapted to engage the drum concomitantlywith the friction element and movable on the thrust pin proportionallyto a differential in wear between the frictional element and the wearresistance part.

5. A brake comprising a rotatable drum, a friction element forcooperation therewith, a fluidY pressure actuated motor, a thrust pinconnecting the motor to the friction element, means in the motor forreturning the friction element to retracted position, and means forautomaticallyV adjusting the friction element to compensate forwearthereof including a stop member frictionally clamped to the thrust pinand normally seated on the motor, said stop member having a wearresistance part adapted to engage the drum simultaneously with thefriction ele-Y ment and being movable on the thrust pin proportionatelyto a differential in wear between the friction element and the wearresistance part.

6. A brake comprising a rotatable drum, a friction element forcooperation therewith, a motor having a piston movable therein and aclosure cap therefor, a thrust pin connecting the piston to the frictionelement,V a. retractile spring between the piston and cap, a stopfrictionally clamped on the thrust pin having a wear resisting partadapted to engage the drum simultaneously with the friction element andmovable lon the pin proportionately to the differential in Wear betweenthe friction element and the wear resistance part.`

7. A brake comprising a rotatable drum, a friction element forcooperation therewith, a fluid pressure actuatedV motor having a pistonmovable therein, and a closure cap provided with an opening, a thrustpin movable through the opening having its ends respectively secured tothe piston and to the friction element, a spring interposed between thepiston and the cap, a stop frictionally clamped on the thrust pin havinga wear resistance part adapted to engage the Vdrum simultaneously withthe friction element, said. stop movable on the thrust pin as a resultof Aa differential in wear between the friction element and the wearresistance part and to seat on the cap when the brake is at rest.

8. Av brake comprising a rotatable drum, corresponding oppositelydisposed friction elements for cooperation therewith, a fluid pressureactuated motor between the elements including a cylinder having thereinoppositely disposed mov able pistons and a closure cap on each end ofthe cylinder, thrust pins securing the pistons to the friction elements,retractile springs sleeved on the thrust pins between the pistons andkcaps, stops for cooperation with the caps frictionallyV clamped on thethrust pins and hav-V ing parts adapted to engage the drumsimultaneously with the friction elements, said stops being movable onthe pins proportionately to the differential in wear between thefriction elements and the wear resistance parts.

y HAROLD L. FRICK.v

REFERENCES CITED The following references are of record in the leof thispatent:

UNITED STATES PATENTS 2,497,815 AFrick Feb. 14, 1950

